全文获取类型
收费全文 | 8454篇 |
免费 | 682篇 |
国内免费 | 565篇 |
专业分类
耳鼻咽喉 | 39篇 |
儿科学 | 63篇 |
妇产科学 | 30篇 |
基础医学 | 1327篇 |
口腔科学 | 93篇 |
临床医学 | 255篇 |
内科学 | 483篇 |
皮肤病学 | 135篇 |
神经病学 | 230篇 |
特种医学 | 76篇 |
外国民族医学 | 3篇 |
外科学 | 185篇 |
综合类 | 1491篇 |
现状与发展 | 1篇 |
预防医学 | 597篇 |
眼科学 | 94篇 |
药学 | 1882篇 |
中国医学 | 2530篇 |
肿瘤学 | 187篇 |
出版年
2024年 | 24篇 |
2023年 | 80篇 |
2022年 | 216篇 |
2021年 | 294篇 |
2020年 | 240篇 |
2019年 | 201篇 |
2018年 | 231篇 |
2017年 | 294篇 |
2016年 | 328篇 |
2015年 | 352篇 |
2014年 | 578篇 |
2013年 | 720篇 |
2012年 | 655篇 |
2011年 | 711篇 |
2010年 | 537篇 |
2009年 | 434篇 |
2008年 | 457篇 |
2007年 | 452篇 |
2006年 | 352篇 |
2005年 | 312篇 |
2004年 | 255篇 |
2003年 | 218篇 |
2002年 | 227篇 |
2001年 | 155篇 |
2000年 | 118篇 |
1999年 | 124篇 |
1998年 | 123篇 |
1997年 | 105篇 |
1996年 | 89篇 |
1995年 | 75篇 |
1994年 | 86篇 |
1993年 | 62篇 |
1992年 | 62篇 |
1991年 | 49篇 |
1990年 | 42篇 |
1989年 | 47篇 |
1988年 | 46篇 |
1987年 | 34篇 |
1986年 | 35篇 |
1985年 | 55篇 |
1984年 | 49篇 |
1983年 | 41篇 |
1982年 | 39篇 |
1981年 | 24篇 |
1980年 | 25篇 |
1979年 | 14篇 |
1978年 | 10篇 |
1977年 | 7篇 |
1976年 | 6篇 |
1974年 | 4篇 |
排序方式: 共有9701条查询结果,搜索用时 15 毫秒
11.
Jocivania O da Silva Renata S Fernandes Fábio K Ticli Clayton Z Oliveira Maurício V Mazzi Jo?o J Franco Silvana Giuliatti Paulo S Pereira Andreimar M Soares Suely V Sampaio 《Toxicon》2007,50(2):283-291
We report here the antiproteolytic and antihemorrhagic properties of triterpenoid saponin inhibitors, named macrolobin-A and B, from Pentaclethra macroloba, against Bothrops snake venoms. The inhibitors were able to neutralize the hemorrhagic, fibrin(ogen)olytic, and proteolytic activities of class P-I and P-III metalloproteases isolated from B. neuwiedi and B. jararacussu venoms. Clotting and fibrinogenolytic activities induced by snake venoms and isolated thrombin-like enzymes were partially inhibited. Furthermore, the potential use of these inhibitors to complement antivenom therapy as an alternative treatment and/or used as molecular models for development of new therapeutical agents in the treatment of snake bite envenomations needs to be evaluated in future studies. 相似文献
12.
J. Belchi-Hernandez S. Moreno-Grau F. Sánchez-Gascón J. Bayo B. Elvira Rendueles B. Bartolomé J. M. Moreno J. Martinez Quesada R. Palacios Peláez 《Allergy》1998,53(3):241-248
Zygophyllum fahago is a herbaceous plant found widely in the Mediterranean area. There are no previous reports of its allergenicity. An aerobiologic and clinical survey was conducted in Murcia, southern Spain, to determine the quantity of airborne pollen and establish the possible role of this pollen as a cause of allergic symptoms. With a Hirst volumetric trap, we determined the atmospheric concentrations of this pollen in 1993, 1994,1995, and 1996. Of 1180 patients tested, 181 (15,34%) had a positive skin test. To determine its allergenicity, we divided 47 patients into three groups: in group 1, all the patients had symptoms of rhinoconjunctivitis plus asthma; in groups 2 and 3, rhinoconjunctivitis. In group 1, we performed a bronchial provocation test (BPT): in groups 2 and 3, we performed nasal provocation (NPT) and conjunctival provocation (CPT) tests, respectively, SDS-PAGE was used to characterize the antigenic fractions and RAST inhibition to determine cross-reactivity with other pollens. The pollen dispersion period is from May to September (445 grains/m3 ), BPT was positive in 13 of 15 patients, NPT in 14 of 16 patients, and CPT in 13 of 16 patients. RAST inhibition revealed cross-reactivity with Mercurialis, Ricinus, Olea. and Betula. SDS-PAGE identified 25 IgE antibody-binding components, five of which (60, 65, 41, 38, and 15.5/14,7 kDa) were recognized by 40% of the sera. By SDS-PAGE immunoblotting with sunflower antiprofilin rabbit serum and affinity chromatography we established that the Z. fahago extract has profilin. This study shows that this pollen becomes airborne and elicits an IgE response which triggers respiratory symptoms in allergic subjects. 相似文献
13.
法半夏罗汉果川贝枇杷膏与强力枇杷露药理作用的比较研究 总被引:3,自引:0,他引:3
法半夏罗汉果川贝枇把膏与强力批他露均有镇咳祛痰作用,罗汉果川贝枇把膏尚能平喘抗炎。 相似文献
14.
在竹叶及其提取物中检出了相当含量的一种羟化赖氨酸—δ-OH-Lys,主要以游离单体和小肽的形式存在。从桂竹和金毛竹叶样分别测得其含量占干叶氨基酸总量的1.33%和1.40%,约相当于其中Lys含量的1/4.醇-水提取的过程有富集δ-OH-Lys的作用,其在提取物中的含量远远高于Lys.这一特殊的非蛋白氨基酸以相当含量存在于竹叶中,可能有着特殊的生物学意义。 相似文献
15.
介绍了一种从谷朊粉废水中提取戊聚糖的工艺,由此工艺得到的产品(戊聚糖质量分数约70%,蛋白质质量分数约20%)能较好地保持戊聚糖的特性.研究了其它添加剂(卡拉胶)对戊聚糖的乳化性,戊聚糖对肉制品持油、持水性以及其质构的影响.谷朊粉废弃水提取物与卡拉胶的复配产品在添加量(质量分数)为6%时能使肉制品有较好的持油性和相应的质构. 相似文献
16.
17.
目的探讨不同摄食控制方法对荷瘤小鼠生存期的影响。方法摄食控制组分别为每日限食2.0 g(DR)、隔1日断食限食4.0 g(IF)、隔2日断食限食6.0 g(SF)和隔1日断食不限食(IF1)4种方法,正常摄食为空白对照组(AL)。观察各组小鼠的体重变化和平均存活天数。结果DR组和IF组平均存活天数分别为19.52±5.24 d和17.96±4.49 d,比对照AL组15.75±1.83 d明显延长(P<0.001和P<0.01)。结论摄食控制恰当,可明显抑制肿瘤细胞的生长、延长荷瘤小鼠的生存期并提高生存质量。 相似文献
18.
Susi Elaine Dal''Belo Lorena Rigo Gaspar Patrícia Maria Berardo Gonçalves Maia Campos 《Skin research and technology》2006,12(4):241-246
BACKGROUND/PURPOSE: The polysaccharide-rich composition of Aloe vera extracts (Aloe barbadensis Miller), often used in cosmetic formulations, may impart moisturizing properties to the product. The aim of this study was to evaluate the effect of cosmetic formulations containing different concentrations of freeze-dried Aloe vera extract on skin hydration, after a single and a 1- and 2-week period of application, by using skin bioengineering techniques. METHODS: Stable formulations containing 5% (w/w) of a trilaureth-4 phosphate-based blend were supplemented with 0.10%, 0.25% or 0.50% (w/w) of freeze-dried Aloe vera extract and applied to the volar forearm of 20 female subjects. Skin conditions in terms of the water content of the stratum corneum and of transepidermal water loss (TEWL) (Corneometer CM 825 and Tewameter TM 210) were analysed before and after a single and 1- and 2-week period of daily application. RESULTS: After a single application, only formulations supplemented with 0.25% and 0.50% (w/w) of Aloe vera extract increased the water content of the stratum corneum, while after the 2-week period application, all formulations containing the extract (0.10%, 0.25% and 0.50%) had the same effect, in both cases as compared with the vehicle. TEWL was not modified after a single and after 1- and 2-week period of application, when compared with the vehicle. CONCLUSION: Our results show that freeze-dried Aloe vera extract is a natural effective ingredient for improving skin hydration, possibly through a humectant mechanism. Consequently, it may be used in moisturizing cosmetic formulations and also as a complement in the treatment of dry skin. 相似文献
19.
以小麦(Triticum aestivum L.)品种石4185为材料,研究了45 ℃处理0~120 min对小麦未成熟籽粒谷甘胱肽转移酶(GST)、谷胱甘肽还原酶(GR)、过氧化氢酶(CAT)和过氧化物酶(POD)活性, 超微弱发光,种子萌发和愈伤组织诱导的影响.结果表明,热休克处理使未成熟籽粒萌发率、愈伤组织诱导率和GST活性明显增加,且其作用随处理时间的延长而增大;在处理过程中, CAT活性先减少后增加,热休克对GR活性无明显影响.GST的活性与蛋白质质量分数呈显著正相关. 相似文献
20.
蝎毒多肽提取物对肺癌荷瘤裸鼠血流变学的影响 总被引:2,自引:0,他引:2
目的观察蝎毒多肽提取物(PESV)对肺癌荷瘤裸鼠血流变学的影响。方法移植肺癌荷瘤裸鼠随机分为PESV组(皮下注射PESV)与对照组(皮下注射生理盐水)。采用FASCO-300型全自动表观黏度快测仪对两组的全血黏度进行检测。结果与对照组相比,PESV组血流变学指标均有不同程度的降低,尤其是全血低切表观黏度、全血高切表观黏度、Casson黏度、Casson屈服应力均明显低于对照组(P〈0.01)。结论PESV可降低荷瘤裸鼠血液黏度,对肺癌荷瘤裸鼠肿瘤转移能力有明显的抑制作用。 相似文献